There are a multitude of varying types of cysts which present as subcutaneous nodules. The classic “sebaceous cyst” is a closed pore that fills with oily sweat and dead skin cells and feel like a marble under the skin. They can rupture making a swollen red “boil”. A Dermatologist can identify different entities and offer the best advice regarding watching and waiting, surgical excision, incision and drainage or treatment with pain reducing injections.